Telescopes & Astronomy

The ZWO 7nm OIII filter is centered around the Oxygen III band of 501nm. Oxygen III or double ionised oxygen occurs at  primarily at 500.7nm and secondarily 495.9nm.  The highest levels of OIII are usually found in diffuse and planetary nebulae. The OIII emission lines were first discovered in the 1860s in spectra of planetary nebulae.  OIII wavelengths relate to the green-turquoise-cyan in colour on the spectrum whilst the narrowband width makes the background space very black.

Bring out the best in your nebulae astroimages with the H-alpha H-beta OIII (Hα-Hβ-OIII) Imaging Filter for the 8” RASA. This specialized filter allows high transmission of light from emission nebulae while blocking light pollution, helping to make your images pop with detail off the black sky background with superior contrast.

Fortunately, many sources of light pollution have relatively discreet emission spectra; they emit primarily at specific wavelengths of light. By strategically blocking these “bad” wavelengths, the filter essentially eliminates the effect of light pollution while letting the “good” wavelengths of light associated with the emission nebula pass through to the camera. You’ll notice much higher contrast in your images immediately, even if imaging from your light polluted backyard! And since the transmission at the key wavelengths is so high, the nebula will not be dimmed—only the background will be blacker.

• Compatible With E-3 Type Remote Control Terminal
• Electronic Shutter Release Cable
• Connect Your DSLR Camera to Sky-Watcher Computerised Mount
• 5 Years Australian Manufacturer Warranty

M42 x 0.75mm Aluminium Alloy Extension Spacer Ring for telescope photography. This 5mm spacer can help you achieve precise back-focus spacing in your imaging train.

• Most accurate way to guide – improved accuracy compared to using a separate guide scope
• 12.5 mm multi-coated prism with aluminized backing for maximum reflectivity and illumination to the autoguider
• Fixed-orientation helical focuser for easy, smooth and accurate autoguider focus
• 48mm clear aperture supports full frame cameras without vignetting
• Includes adapters with the correct spacing for DSLR cameras, Nightscape CCD and other popular astroimaging cameras
• Ideal for Schmidt- Cassegrain and EdgeHD telescopes

• Create an extra auxiliary port on your Celestron computerized mount with this AUX Port Splitter
• Two auxiliary ports are required to use accessories like the Celestron StarSense AutoAlign on telescopes with only one built-in AUX port
• Adapter has two 6-pin auxiliary outputs and one 6-pin input